This invention relates to a method for producing a metal protective sheath for the edge of an aerodynamic blade and more particularly relates to a unique process for making such a sheath from multiple components for use on the edge of a high strength, high modulus, nonductile filament reinforced composite blade.
It is known to provide protection, particularly from foreign object impact damage, by providing a metal sheath to the leading edge of a gas turbine fan blade. Typically, such sheaths are made either by machining from a solid piece of metal or by brazing a plurality of components together with an appropriate braze alloy.
Machining a sheath is a costly and relatively inefficient procedure. However, recourse to other techniques, such as the use of brazing materials has been less than satisfactory since (1) the relatively high braze temperatures badly compromise or severely reduce the mechanical properties of the sheath and (2) with titanium or titanium alloy sheaths the use of titanium braze alloys may result in marked corrosion susceptibility.